1. Field of the Invention
This invention relates to apparatus actuated to provide an indication of a direction of movement during an electrical power failure or during a fire emergency.
2. Summary of the Background Information
A number of patents describe methods for actuating lights indicating a direction of movement for personnel when a fire has been detected. For example, U.S. Pat. No. 3,969,720 describes a fire alarm, a plurality of indicator lights arranged in a line toward an emergency exit, and an operating unit, coupled to the alarm, being operable in response to an output signal in from the alarm to successively energize the indicator units in the direction of the exit. Each of the indicator units includes a light and a buzzer. U.S. Pat. No. 4,801,928 describes a system including an indicator unit having at least three electroluminescent lamps in a linear arrangement and circuitry for sequentially illuminating the lamps in a repeated manner from one end of the arrangement to the other. The electronic circuitry is also provided to sequentially illuminate a group of electroluminescent lamps in one direction in response to in one direction in response to a first sensed condition of relative danger and in another direction in response to a second sensed condition of relative danger. For example, a smoke detector is placed near each of two exits, with the lights being activated upon the detection of smoke to cause movement toward the exit at which smoke is not detected. What is needed is a system in which the same arrangement of lights can be flashed in different sequences to indicate different directions of movement.
Modern airliners include strips of lights extending in rows along the floor, with means being provided to flash the lights in sequences indicating the available paths for escape in the event of an aircraft fire. A system of this type is described in U.S. Pat. No. 4,347,499, with the operation of the sequentially flashed lights being responsive to sensing means determining the availability of an exit for use. The lights of such systems are mounted in slots extending along the floor. What is needed in for fire protection within a building is a modular system including units flashing lights to indicate a desired direction of movement that can easily be installed wherever electrical service is provided.
Other patents describe apparatus providing for different types of lighting indications upon the detection of a fire. For example, U.S. Pat. No. 6,249,221 describes an escape system for helping a person find an exit door during an emergency providing limited visibility. The system includes at least one heat detector, at least one smoke detector, an audible alarm circuit, a dynamic pulsating door base light, and, optionally, an additional continuous door base light. U.S. Pat. No. 4,531,114 describes an alarm system including exit sign units coupled to a smoke sensor and a heat sensor for input information and to a speech synthesizer and a strobe light for providing output information. A communication unit provides communication coupling between sign units on a single floor and between interfaces between floors and a central monitoring unit. U.S. Pat. No. 5,996,620 describes a building fire alarm system including a network of light strobes arranged to flash simultaneously.
Other patents describe alarm systems including apparatus for providing back-up electrical power in the event of a power failure, with the back-up power being used to maintain operation of devices for detecting and indicating dangerous conditions. For example, U.S. Pat. No. 3,916,404 describes a personnel protection system including a danger detecting system, such as a thermally operated electronic controller covering an area under protection, a distinctive audible alarm system, and visual directing means indicating the location of one or more exits and the direction in which a suitable exit lies. An auxiliary electric power supply system stands in reserve to operate the detector circuits, a flashing light circuit, and warning sound circuits from a storage battery. U.S. Pat. No. 4,199,734 describes a home security system including a fire detector, an audible alarm, and a battery for operation in the event of a power failure. The system also provides emergency lighting during a power failure, with the lighting being turned off if the battery voltage gets too low so that the alarm function can be maintained.
U.S. Pat. No. 4,422,069 describes a system including at least one, and preferably two, flashable lights positioned near an exit door to be activated in case of an emergency, such as a fire or interruption of power. The lights are preferably located near the floor on opposite sides of the exit and are energized by emergency power supply batteries upon interruption of the main power supply, which may be interrupted by a fire detection device.
Other patents describe apparatus providing illumination in the event of a power failure without provisions for a fire alarm. For example, U.S. Pat. No. 3,869,639 describes a circuit for driving at least one gaseous discharge lamp from alternating current during normal conditions and from a battery during a power failure. U.S. Pat. No. 6,049,178 describes a circuit for maintaining illumination of an emergency exit light during a power failure. What is needed is a system providing indication of a preferred direction of movement in the event of a power failure.